Extreme hyperferritinemia in the pediatric emergency setting: haemophagocytic lymphohistiocytosis, macrophage activation syndrome, sepsis and more

Ferritin plays an important role in modulating inflammation and is a significant marker in some life-threatening pathological conditions. Hemophagocytic lymphohistiocytosis (HLH), macrophage activation syndrome (MAS), sepsis, and the more recent multisystem inflammatory syndrome in children (MIS-C) share many clinical and laboratory aspects, including the increase in ferritin levels, so that they are considered hyperferritinemic syndromes. In the pediatric emergency setting, the finding of high ferritin levels if associated with fever requires considering these rare syndromes to start a timely therapy.